Method and apparatus for the processing of carbon-containing polymeric materials

ABSTRACT

A method for the processing of carbon-containing polymeric material, the method comprising the steps of: Introducing the carbon-containing polymeric material into the retort of a retort assembly which includes a retort disposed at least partially within the combustion chamber, the retort containing an inert heat-transfer medium and an agitation means, wherein the agitation means is adapted to agitate the inert heat transfer medium and the carbon containing polymeric material, the combustion chamber having heating means to indirectly heat the rotatable retort; Heating the carbon-containing polymeric material and the inert heat transfer medium to cause such to at least partially decompose; Discharging processed carbon-containing polymeric material from the retort.

FIELD OF THE INVENTION

The present invention relates to a method for the processing ofcarbon-containing materials and an apparatus when used for theprocessing of carbon-containing materials. More specifically, the methodand apparatus of the present invention relate to the processing ofcarbon-containing polymeric materials, including tyres, plastics, andpaper.

BACKGROUND ART

Waste products comprising carbon-containing polymeric materialsconstitute one of the most significant environmental problems facing theworld today. Polymeric materials make up a significant fraction ofmunicipal solid waste, reaching up to 50% of the total volume, asestimated by the U.S. Environmental Protection Agency. Recyclingtechnologies, faced with difficulties such as having to segregatedifferent types of plastics, poor economics and low quality finalproducts, have failed to address the problem. The non-biodegradabilityof such polymeric waste material presents further problems.

Present methods and/or apparatus for the processing of carbon-containingpolymeric materials have been directed to the processing of specificcarbon-containing polymeric wastes. It is one object of the presentinvention to provide a method and apparatus for the processing ofcarbon-containing waste materials that is capable of processing a widerange of carbon-containing polymeric waste materials, including mixedproducts, such as different types of plastics.

The preceding discussion of the background to the invention is intendedto facilitate an understanding of the present invention. However, itshould be appreciated that the discussion is not an acknowledgement oradmission that any of the material referred to was part of the commongeneral knowledge in Australia as at the priority date of theapplication.

Throughout the specification, unless the context requires otherwise, theword “comprise” or variations such as “comprises” or “comprising”, willbe understood to imply the inclusion of a stated integer or group ofintegers but not the exclusion of any other integer or group ofintegers.

DISCLOSURE OF THE INVENTION

In accordance with the present invention, there is provided anapparatus, when used for the processing of a carbon-containing polymericmaterial, the apparatus comprising a retort assembly which includes aretort disposed at least partially within a combustion chamber, theretort containing an inert heat-transfer medium, and an agitation meansand the combustion chamber having heating means to indirectly heat theretort, wherein the agitation means is adapted to agitate the inert heattransfer medium and the carbon containing polymeric material.

Similar apparatus have been described for the separation of volatilematerials from soils and the like. In such applications, the aim is toseparate the volatile material from the medium with a minimum ofchemical degradation of the volatile material. However, a primary aim ofthe treatment of carbon-containing polymeric materials involves chemicaldegradation of the polymeric materials by processes such as pyrolysis.It has been found that the enhanced heat transfer properties of theretort and the ability to control residence times afforded by theagitation means, are advantageous in applications requiring thebreakdown of polymeric materials.

The application of apparatus for the processing of carbon-containingmaterials similar in design and operation to those described for theseparation of volatile materials offers tremendous potential as itallows the user considerable flexibility. The dual application of theequipment of the present invention is counter-intuitive to its existingapplications. Whilst the thermal desorption is a separation process thatattempts to minimise breakdown of the products fed into the unit,pyrolysis is a physicochemical process that aims to synthesise newcompounds by producing the breakdown, combination, and molecularrearrangement of the initial products.

Commercial interest in the pyrolysis process is hence increased whenpyrolysis is maximised and separation of the unreacted initial productsis minimised. Moreover, the process offers a higher commercial potentialwhen pyrolysis is carried out under controlled conditions, where theoperator can control a set of variables that would allow him toselectively synthetise certain fractions.

Preferably, the agitation means is adapted to agitate the inert heattransfer medium and the carbon containing polymeric material to create afluidised bed, or fluidised bed-like effect.

Preferably, the agitation means is controllable, whereby the residencetime of the solid material in the retort may be controlled.

In one form of the invention, a longitudinal axis of the retort isinclined to the horizontal, and is bottom fed. Preferably, thelongitudinal axis of the retort is substantially vertical and the retortis bottom fed. Preferably, where the retort is substantially verticaland the retort is bottom fed, the agitation means is further adapted tofacilitate the transport of the polymeric material and the inertheat-transfer medium through the retort. In one form of the invention,the agitation means is provided in the form of an auger.

Preferably still, the retort is adapted to allow the exclusion of air oroxygen.

The apparatus and process object of the present invention offer themeans to control key variables that affect the final composition andcharacteristics of the fractions obtained by pyrolysis, whilst allowingfor the processing of a wide range of products. This is a distinctivedifference with other pyrolysis processes that do not allow for thecontrol of variables such as residence time.

The application of such technologies known for the treatment ofcontaminated soils to the processing of carbon-containing polymers isalso hindered by a number of factors, due to their design and operation.Directly fired thermal desorbers are designed to process soil withvolatile compounds. These apparatus produce the combustion of thepolymers or hydrocarbons contained in the soil. Indirectly fired thermaldesorbers, if operating in the presence of oxygen or air, do cause thedegradation of compounds by oxidation or partial combustion, which alsocompromises their capabilities as controlled-pyrolysis apparatus. Moreimportant, all of these machines are designed to remove volatile orsemi-volatile compounds from solids or sludge. Their use as pyrolysisreactors is impeded by their design and operation, mainly their heattransfer processes, fluid mechanics, the absence of a solid inert heattransfer medium inside the unit, and residence time, and morespecifically, their inability to process pure polymers.

In one form of the invention, the retort comprises a substantiallycylindrical body.

In one form of the invention, the substantially cylindrical body ismounted for rotation about its longitudinal axis.

The agitated retort allows for the control of the residence time, theretaining of the heat transfer medium, an intimate contact with saidheat transfer medium, and the possibility to add other chemicals such ascracking catalysts to enhance the process.

Preferably still, the retort is substantially surrounded by thecombustion chamber to enable direct heating of the retort.

Preferably, the apparatus further comprises a high temperature filterthrough which the gaseous stream may pass after leaving the retort andprior to entering the afterburner.

In one form of the invention, the heat transfer medium is provided inthe form of sodium silicate, or sand.

In another form of the invention, the heat transfer medium is providedin the form of alumina.

In one form of the invention, the retort contains one or more catalystto improve the ratio of some of the fractions of the final products overthe total of products obtained from the pyrolysis. These catalysts areof the type used in petroleum refining operations, in the cracking ofhydrocarbons, obvious to those skilled in the art.

In a further form of the invention, the apparatus additionally comprisesan afterburner, means to transfer a gaseous stream from the retort tothe afterburner for combustion and means for passing the combustiongases from the afterburner to the retort assembly to provide heat forheating carbon-containing polymeric material in the retort.

In one form of the invention, the apparatus further comprises one ormore condensers wherein each condenser is adapted to condense gaseousproducts produced by heating the polymeric material.

In one form of the invention, the apparatus further comprises acombustion engine, wherein the engine is adapted to receive and befuelled by condensed gaseous products produced by heating the polymericmaterial until it decomposes, pyrolyses or desorbs. In one form of theinvention, the engine is a gas turbine adapted to generate electricityfrom the gases produced from the decomposition of the polymericmaterials, without prior condensation.

In accordance with the present invention, there is provided a method forthe processing of carbon-containing polymeric material, the methodcomprising the steps of:

-   -   Introducing the carbon-containing polymeric material into the        retort of a retort assembly which includes a retort disposed at        least partially within the combustion chamber, the retort        containing an inert heat-transfer medium and an agitation means,        wherein the agitation means is adapted to agitate the inert heat        transfer medium and the carbon containing polymeric material,        the combustion chamber having heating means to indirectly heat        the rotatable retort;    -   Heating the carbon-containing polymeric material and the inert        heat transfer medium to cause such to at least partially        decompose;    -   Discharging processed carbon-containing polymeric material from        the retort.

Preferably, the agitation means is adapted to agitate the inert heattransfer medium and the carbon containing polymeric material to create afluidised bed, or fluidised bed-like effect.

Preferably, the agitation means is controllable, whereby the residencetime of the solid material in the retort may be controlled.

In one form of the invention, a longitudinal axis of the retort isinclined to the horizontal, and is bottom fed. Preferably, thelongitudinal axis of the retort is substantially vertical and bottomfed. Preferably, where the retort is substantially vertical and bottomfed, the agitation means is further adapted to facilitate the transportof the polymeric material and the inert heat-transfer medium through theretort. In one form of the invention, the agitation means is provided inthe form of an auger.

Preferably still, the retort is adapted to allow the exclusion of air oroxygen.

In one form of the invention, the retort comprises a substantiallycylindrical body.

In one form of the invention, the substantially cylindrical body ismounted for rotation about its longitudinal axis.

Preferably still, the retort is substantially surrounded by thecombustion chamber to enable direct heating of the retort.

Preferably, the apparatus further comprises a high temperature filterthrough which the gaseous stream may pass after leaving the retort andprior to entering the afterburner.

In one form of the invention, the heat transfer medium is provided inthe form of sodium silicate, or sand.

In another form of the invention, the heat transfer medium is providedin the form of alumina.

In another form of the invention, the retort contains one or morecatalyst to improve the ratio of some of the fractions of the finalproducts over the total of products obtained from the pyrolysis. Thesecatalysts are of the type used in petroleum refining operations, in thecracking of hydrocarbons, obvious to those skilled in the art.

Preferably, the steps of the method are performed concurrently.

In a preferred form of the invention, the method comprises the furtherstep of:

-   -   Controlling the rate of passage of the carbon-containing        polymeric material through the retort, such that the        carbon-containing polymeric material is retained in the retort        for a predetermined residence time.

Preferably, the step of heating the carbon-containing polymeric materialto cause such to at least partially decompose is performed in asubstantially oxygen-free atmosphere. In a specific form of theinvention, the step of heating the carbon-containing polymeric materialto cause such to at least partially decompose is performed in an inertgas atmosphere. In a highly specific form of the invention, the step ofheating the carbon-containing polymeric material to cause such to atleast partially decompose is performed in an atmosphere substantiallycomprising nitrogen gas.

In a specific form of the invention, the carbon-containing polymericmaterial is provided in the form of one or more tyres.

In another form of the invention, the carbon-containing polymericmaterial is provided in the form of plastics. These plastics can be purestreams of waste polyethylene, polyethylene terphtalate, polypropylene,polystyrene, or PVC, or mixtures thereof. In the case of processingpolymers containing halogens, such as PVC, the invention comprises thetreatment of the gas stream produced from the pyrolysis to removehydrogen chloride.

In another form of the invention, other carbon-containing polymers arefed into the unit, such as paper or wood, where the cellulosic fibresare pyrolysed to produce fractions of shorter molecules with propertiesconsistent with those of liquid fuels obtained from biomass.

Where the carbon-containing polymeric material is provided in the formof tyres, the step of heating the carbon-containing polymeric materialto cause such to at least partially decompose more specificallycomprises the step of heating the tyres to between about 400–800° C.Preferably still, the tyres are heated to between about 450–600° C. In aspecific form of the invention, the tyres are heated to 450° C. Wherethe carbon-containing polymeric material is provided in the form oftyres, the residence time of the tyres in the retort is preferablybetween about 30 and 240 minutes. Preferably still, the residence timeis between about 45 and 180 minutes. In a specific form of theinvention, the residence time is approximately 130 minutes.

Preferably, the method of the present invention takes place atatmospheric pressure or near atmospheric pressure. As would beunderstood by a person skilled in the art, increases in pressure reducethe temperature range.

Where the carbon-containing polymeric material is provided in the formof tyres, the step of introducing the carbon-containing polymericmaterial into the retort of a retort assembly more specificallycomprises introducing the carbon-containing polymeric material into theretort at between approximately 200 kg per hour to 2000 kg per hour.

Preferably, where the carbon-containing polymeric material is providedin the form of tyres, before the step of introducing thecarbon-containing polymeric material into the retort, the method of thepresent invention comprises the preliminary step of shredding the tyres.

Where the carbon-containing polymeric material is provided in the formof plastics, the step of heating the carbon-containing polymericmaterial to cause such to at least partially decompose more specificallycomprises the steps of heating the carbon-containing polymeric materialto melt such before heating the carbon-containing polymeric material topyrolyse such.

Where the carbon-containing polymeric material is provided in the formof plastics, the step of heating the carbon-containing polymericmaterial to cause such to at least partially decompose more specificallycomprises the step of heating the plastic to between about 300 and 1200°C. Preferably still, the plastics are heated to between about 450–1000°C. In a specific form of the invention, the plastics are heated to about550° C.

Where condensate is desired over gaseous products, lower temperatures inthe range of approximately 400–500° C. are used. Where gaseous productsare desired over condensate, higher temperatures may be used.

Where the carbon-containing polymeric material is provided in the formof plastics, the residence time of the tyres in the retort is preferablybetween about 30 and 240 minutes. Preferably still, the residence timeis between about 45 and 120 minutes. In a specific form of theinvention, the residence time is approximately 80 minutes.

Where the carbon-containing polymeric material is provided in the formof a cellulosic material, such as paper or wood, the step of heating thecarbon-containing polymeric material to cause such to at least partiallydecompose more specifically comprises the step of heating the cellulosicmaterial to between about 400 and 800° C. Preferably still, thecellulosic material is heated to between about 450–800° C. In a specificform of the invention, the cellulosic material is heated to about 500°C.

Where the carbon-containing polymeric material is provided in the formof cellulosic material, the residence time of the cellulosic material inthe retort is preferably between about 30 and 240 minutes. Preferablystill, the residence time is between about 45 and 120 minutes. In aspecific form of the invention, the residence time is approximately 80minutes.

The method of the present invention may further comprise the step of:

-   -   Reducing the pressure in the retort to enable lower temperatures        to be used.

The step of discharging processed carbon-containing polymeric materialfrom the retort may include:

-   -   Separating the heat transfer medium from the processed        carbon-containing polymeric material

More specifically, the step of separating the heat transfer medium fromthe processed carbon-containing polymeric material comprises:

-   -   Separating the heat transfer medium from the processed        carbon-containing polymeric material based on density        differences.

In one form of the invention, the carbon-containing polymeric materialdecomposes into at least a gaseous stream.

Where the carbon-containing polymeric material decomposes into a gaseousstream, the method may comprise the step of:

-   -   Filtering the gaseous stream to remove particulate material        therefrom.

Where the carbon-containing polymeric material decomposes into a gaseousstream, the method may comprise the step of:

-   -   Condensing at least a portion of the gaseous stream to produce a        condensate.

The step of condensing at least a portion of the gaseous stream, maymore specifically comprise:

-   -   Fractionating at least a portion the gaseous stream to produce a        range of condensate fractions.

Where the method comprises the step of condensing at least a portion ofthe gaseous stream to produce a condensate, the method may comprise thefurther step of:

-   -   Subjecting the condensate to flash distillation.

Where the carbon-containing polymeric material decomposes into a gaseousstream, the method may comprise the step of:

-   -   Combusting the gaseous stream to provide heat for heating the        carbon-containing polymeric material.

Where the carbon-containing polymeric material decomposes into a gaseousstream, the method may comprise the step of:

-   -   Combusting the gaseous stream in a gas turbine to generate heat        and electricity.

Where the carbon-containing polymeric material decomposes into a gaseousstream, the method may comprise the step of:

-   -   Combusting the gaseous stream in an afterburner or thermal        oxidiser.

In one form of the invention, the carbon-containing polymeric materialdecomposes into at least a solid product.

Where the carbon-containing polymeric material decomposes into a solidproduct, the method may comprise the step of:

-   -   Extracting the solid material from the retort.

The carbon-containing polymeric material may be provided in the form ofa solid or a liquid.

Where the carbon-containing polymeric material is provided in the formof a solid, the carbon-containing polymeric material may be passedthrough a grizzly or sieve, to remove oversized material, prior to beingintroduced into the retort. In one form of the invention, wherecarbon-containing polymeric material may be provided in the form of asolid, in addition to or as an alternative to passing such through agrizzly or sieve, the carbon-containing polymeric material may be milledprior to being introduced into the retort.

Where the carbon-containing polymeric material is provided in the formof a solid, the carbon-containing polymeric material may be shredded ormilled to reduce particle size and may include a separation stage.During this separation stage, metals or other material may be separatedfrom the carbon-containing polymers.

Where the carbon-containing polymeric material is provided in the formof a liquid, the water content of the carbon-containing polymericmaterial is preferably minimised prior to introducing such into theretort. This may be achieved by preheating the liquid carbon-containingpolymeric material to boil off any water.

In accordance with the present invention there is provided an apparatus,when used for the processing of a carbon-containing polymeric material,the apparatus being substantially as described in Australian patent712838, the contents of which are hereby incorporated by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described, by way of example only,with reference to seven embodiments thereof and the accompanyingdrawings, in which:

FIG. 1 is a schematic representation of a portion of an apparatus forprocessing carbon-containing polymeric material;

FIG. 2 is a schematic representation of a gas treatment portion of anapparatus for processing carbon-containing polymeric material inaccordance with a first embodiment of the invention;

FIG. 3 is a schematic representation of a gas treatment portion of anapparatus for processing carbon-containing polymeric material inaccordance with a second embodiment of the invention;

FIG. 4 is a schematic representation of a gas treatment portion of anapparatus for processing carbon-containing polymeric material inaccordance with a third embodiment of the invention;

FIG. 5 is a schematic representation of a gas treatment portion of anapparatus for processing carbon-containing polymeric material inaccordance with a fourth embodiment of the invention

FIG. 6 is a schematic representation of a solids treatment portion of anapparatus for processing carbon-containing polymeric material inaccordance with a fifth embodiment of the invention;

FIG. 7 is a schematic representation of a solids treatment portion of anapparatus for processing carbon-containing polymeric material inaccordance with a sixth embodiment of the invention;

FIG. 8 is a schematic representation of a portion of an apparatus forprocessing carbon-containing polymeric material in accordance with aseventh embodiment of the present invention; and

FIG. 9 is a schematic representation of two models developed todetermine the feasibility of using a fraction of the recovered productsas sources of energy.

It is to be understood that the embodiments are described by way ofexample only, and are not to be construed as in any way limited thescope of the invention as described. Further, it should be understoodthat the features described in two or more embodiments may be combinedto produce an apparatus and/or method for processing carbon-containingpolymeric material within the scope of the present invention.

BEST MODE(S) FOR CARRYING OUT THE INVENTION

In FIG. 1 there is schematically shown a portion of an apparatus forprocessing a carbon-containing polymeric material, comprising a polymerfeed assembly 10, and retort assembly 12. The retort assembly 12 in turncomprises a substantially cylindrical body 14 vertically disposed withina combustion chamber 16, the combustion chamber having heating means(not shown) to indirectly heat the cylindrical body 14.

The retort assembly 12 is substantially similar to the retort assembliesdescribed in Australian Patent 712838, the contents of which are herebyincorporated by reference.

The retort assembly 12 further comprises an auger or stirrer 18 toagitate the contents of the retort and drive the product from the feedpoint to the outlet and provide an adequate residence time. Anextraction system 18 b such as an auger is adapted to extract solidmaterial from the cylindrical body 14. The cylindrical body 14 containsan inert heat transfer medium in the form of sand.

Carbon-containing polymeric material is fed into the cylindrical body14, which is heated by way of the combustion chamber 16 causing,depending on the conditions applied within the cylindrical body 14, thecarbon containing polymeric material to thermally decompose into agaseous phase 20, and/or a solid phase 22 in varying proportions. Thedecomposition of the carbon-containing polymer is achieved by both heatand residence time, with the residence time regulated by the movement ofthe stirrer or auger 18 b that carries the carbon-containing polymer andthe inert heat transfer medium in a resulting upward path from the inletfed by the polymer feed assembly 10 to the outlet, thereby forming afluidised bed-like arrangement. The gas stream 20, produced by thedecomposition or desorption of the carbon-containing polymer subjectedto indirect heat, is driven off the retort 14 by the effect of thevaporisation and the difference in pressure between the retort 14 and afiltration assembly 24. The solid phase 22 is removed from thecylindrical body 14 by way of the auger 18 b, and separated from theheating medium based on differing densities. The gaseous phase 20 isthen passed through the filtration assembly 24.

Referring now to FIG. 2, in a first embodiment the gaseous phase 20 isthen be passed to an afterburner or thermal oxidiser 26, where the gasesare subjected to combustion. Gases produced by the afterburner may besubjected to further treatment.

Referring now to FIG. 3, in a second embodiment, after passage throughthe filtration assembly 24, the gaseous stream is condensed, totally orpartially, by way of a series of condensers 28 to produce one or morecondensates 29. Uncondensed gases may be passed to an afterburner 26 asdescribed in the first embodiment, or directly treated.

Referring now to FIG. 4, in a third embodiment, after passage throughthe filtration assembly 24, the gaseous stream may be fed directly intoa gas turbine 30, by which heat 32 and electricity 34 are generated. Theelectricity 34 is supplied to a power grid or used to supply power tothe process. The heat 32 produced by the gas turbine 30 and may be usedto heat the cylindrical body 14. At least a portion of the heat may alsobe used in other processes such as evaporation of water or pre-heatingof the carbon-containing polymeric material. Referring now to FIG. 5, ina fourth embodiment, the condensate 29 formed in the second embodimentis passed through a flash distillation assembly 36, to furtherfractionate such.

Referring now to FIG. 6, in a fifth embodiment, the solid material 22 isheated in a further retort assembly 40 to produce a carbon product 42,and may be combined with one or more additives 38. The heat may beproduced by the gas turbine 30 or an engine. The product 42 hasapplications in the processing of contaminated water or contaminatedgas, in the removal of organic compounds and heavy metals.

Referring now to FIG. 7, in a sixth embodiment, the solid material 22may contain metals. For example, the carbon product 22, produced as aresult of processing tyres, may contain zinc. The solid material 22 maythen be processed in an agitated vessel 44. A leaching solution may beadded to the agitated vessel 44 to extract the metal, producing ametal-rich leachate. The metal-rich leachate may be processed further byaddition of other compounds or by crystallisation or evaporation, toproduce a product 45. In one such application, product 45 can be sold asa liquid fertilizer. Referring finally to FIG. 8 there is schematicallyshown a portion of an apparatus for processing a carbon-containingpolymeric material, comprising a polymer feed assembly 46, a firstretort assembly 48 and a second retort assembly 50. Each retort assembly48 or 50 in turn comprises a substantially cylindrical body 52vertically disposed within a combustion chamber 54. Each retort assembly48 or 50 further comprises an auger or stirrer 56, to agitate thecontents of the retort and drive the product from the feed ponit to theoutlet and provide an adequate residence time. An extraction system 56b, such as an auger is adapted to extract solid material from thecylindrical body 52.

Carbon-containing polymeric material is fed into the cylindrical body 52of the first retort assembly 48, and heated indirectly within thecylindrical body 52 by way of the combustion chamber 54 thereof. Agaseous stream 57, produced thereby is passed through a filtrationassembly 58, with the remaining partially processed carbon-containingpolymeric material is then passed to the second retort assembly 50 forfurther treatment. Remaining solid material 60 is processed as describedin the context of FIGS. 6 and 7.

Having passed through the filtration assembly 58, two options arepossible. In a first option, the gas stream 62 Is directed to a gasturbine 64. Electricity produced by the gas turbine 64 may be used topower the plant 76 or fed into an electricity grid 78. Heat is alsoproduced by the gas turbine 64. This heat can be used as part of theprocess to provide heat for the first and second retort assemblies 48and 50. The second option involves the condensation of the gas stream66, which is condensed by way of a series of condensers 68 to produce acondensate 70. The condensate Is used to fuel a combustion engine 72,coupled to a generator 74. Heat produced by the combustion engine 74 isfed back to the first retort assembly 48, whilst the electricityproduced by 74 may be used to power the plant or fed into an electricitygrid.

Experimental Trials

Experimental trials were conducted in a unit comprising a verticalretort filled with sand as a heating medium, agitated with a helicoidalmixer. The mixer's speed could be regulated. The product is fed at thebottom of the vessel and is driven upwards in a fluidized bed regime,while it is subjected to heat supplied by two burners that heat the sandfrom an external combustion chamber. Products that are pyrolysed flowthrough the heat bed towards the gas treatment system. The pyrolysedsolid is extracted from the top part of the vessel by a screw auger,whilst the gas is maintained at high temperature so it does not condensewhen it passes through the High Temperature Filter (HTF). The HTFremoves particles from the gas stream, before this gas passes through awater-cooled condenser that separates condensable fractions. Twoconfigurations were used. In the first one, an After Burner was used todestroy the non-condensed products, whilst in the second configuration asecond condenser cooled with a glycol-water solution was used toincrease recovery of hydrocarbons.

The whole system is PLC-controlled, with temperature, pressure, oxygencontent and flows regulated by the system. The plant is described inFIGS. 1 and 3 discussed above.

The unit had a nominal capacity of two tonnes per hour. Throughput ofthe unit depends on a number of variables and the physicochemicalcharacteristics of the feed. Moisture content, density, viscosity,calorific capacity, and composition have an effect on heat requirements,processing rates, and end products.

Two variables are important in the process: temperature and residencetime. Operating temperature in the retort is the key variable thataffects pyrolysis and thermal decomposition, with the quality andcomposition of the final products being in direct relationship to theoperating temperature. Residence time is the other important variable,which affects composition of the final products and feed rates. Thedegree of cracking and decomposition is directly proportional toresidence time. The unit further comprised a feeding hopper and screwconveyor to be able to feed granulated tyres into the retort.

1. Tyres

The trials consisted of the thermal pyrolysis of granulated tyres, witha particle size of 5 mm, screened of metal and fluff. Tests 0014, 0015,and 0016 were carried out using a TDPP configuration (see FIGS. 1 and3). Analysis of the granulate tyres is presented in Table I:

TABLE I Analysis of granulated tyres Parameter Result (in mg/kg)⁽¹⁾Result (in mg/kg)⁽²⁾ Antimony <5.0 <0.5 Cadmium <1.0 0.63 Calcium 3604290 Mercury <0.50 <0.2 Nickel <1.0 1.7 Sodium 49 340 Arsenic <0.5Silicon 260 Chromium 1.6 Phosphorus 110 Iron 300 Copper 30 Vanadium <0.5Sulfur — 18400 Tin <2.0 1.2 Zinc — 13400 Hydrocarbons(*) C6–C9 <25 NdC10–C14 97 45 C15–C28 12000 22000 C29–C36 46000 49000 Total 58000 71000Ash content 41000 36,000 Moisture 0.5% Calorific value 37.21 MJ/kg (*)Ona dry basis ⁽¹⁾Test 0014 and 0015 ⁽²⁾Test 0016, samples020417-01-S-Feed-1020 and 020417-02-S-Feed-1020

The first set of trials, called for the running of two trials at twofeed rates, to test the capabilities of the unit to process the feedmaterial and handle the produced gases. The process conditions aresummarized in Table II.

TABLE II Process conditions Parameter Test 0014 Test 0015 Temperatureretort   450° C.  450° C. Feed rate   75 kg/hour  130 kg/hour Time   20hours   20 hours Pressure HTF clean side  0.1 in H₂O  0.1 in H₂OTemperature condenser outlet   20° C. max   20° C. max Temperatureafterburner   760° C. min  760° C. min Volume processed  1750 kg  625 kgVolume condensed   598 kg  166 kg Volume of solids produced   900 kg 330 kg

Nitrogen was used as a blanketing inert gas to inhibit both oxidationand combustion during the process. Condensing of the generated gas wasachieved by means of the on-line condenser, with cooling watercirculated from the cooling tower.

The second set of trials was designed to prove the limits of the plantin terms of heat transfer and capacity. Sampling of the gas before andafter the After Bumer was also to be completed by a third party, withthe samples analyzed for VOCs, SVOCs, PAHs, Dioxins and Furans,particulates, SOx, and heavy metals. The process conditions aresummarized in Table V.

TABLE V Process conditions Parameter Test 0016 Temperature retort  450°C. Feed rate From 150 kg/hour to 350 kg/hour Time   80 hours PressureHTF clean side  0.1 in H₂O Temperature HTF bottom  450° C. minTemperature condenser HX-03 outlet   30° C. max Temperature condenserHX-04 outlet   10° C. max Temperature afterburner  760° C. min

TABLE VI Process variables Parameter Test 0016 Feed rate 12% 15% 17.5%20% 12% 15%(*) 25%(**) 15%(***) Feed rate 180 225 263 300 180 225 375225 (calculated based on 12% = 180 kg/hour) Average feed 195 kg/hour,calculated from volume processed in total time of feeding rate (64.59hours) Volume 12,531 kg from weight of material processed Volume 16,250kg calculated from feed rates processed Volume 4,634 kg in HX-03condensed 307 kg in HX-04 Volume of 3,208 kg (estimated) solids produced825 kg from HTF (*)The feed rate varied from 12 to 20% (**)This is anestimated average (***)The feed rate varied from 15 to 23%

Pyrolysis of tyres produces three streams: a hydrocarbon-rich oil, asolid char, and gas. The condensed oil was evaluated as a fuelsubstitute, or as a raw material for the separation of valuablefractions. The results are summarized in Table VI.

TABLE VI Analysis of condensed oil Parameter Method C-11 C-12 C-13Sulfur (% w/w) ASTM D5185 0.82 1.11 1.34 Density, 15° C. (kg/l) ASTMD4052 0.9116 0.9106 0.9336 Ash (% w/w) ASTM D482 0.0030 0.0270 0.0060Copper corrosion, ASTM D130 2b 3a 2b 3 hours, 100° C. Cetane Index ASTMD4737 31 31 31 Carbon residue ASTM D4530 1.18 1.40 1.79 (% w/w)Particulate matter ASTM D2276 656 106 82 (mg/l) Flash point (° C.) ASTMD3828 <24 <24 <24 Viscosity, 40° C. (cSt) ASTM D445 1.72 1.35 1.54Metals (mg/kg) ASTM D5185 Iron 2 2 3 Chromium <1 <1 <1 Cupper 4 1 <1 Tin<1 <1 <1 Lead <1 <1 <1 Silica 5 4 1 Aluminum <1 <1 <1 Sodium <1 <1 <1Phosphorus <1 <1 <1 Zinc <1 <1 <1 Calcium <1 <1 <1 Lithium <1 <1 <1Vanadium <1 <1 <1

TABLE VII Analysis of hydrocarbons in condensed oil by GC/MS ParameterC-1 C-2 C-3 C-5 C-6 C-7 Benzene (% w/w) 0.24 0.86 0.65 1.10 0.61 2.20Toluene (% w/w) 1.50 3.80 2.70 3.80 2.70 7.90 Ethyl Benzene (% w/w) 0.821.70 1.60 2.40 2.50 4.10 Xylenes (% w/w) 1.80 3.70 3.20 3.50 2.50 7.40Total 4.36 10.06 8.15 10.80 8.31 21.60 Hydrocarbon fractions C6–C9 9.619.0 15.0 16.0 15.0 26.0 C10–C14 36.0 32.0 28.0 27.0 33.0 25.0 C15–C2933.0 22.0 31.0 31.0 27.0 19.0 C29–C36 0.4 0.1 1.7 1.9 0.1 0.5 Total 79.073.1 75.7 75.9 75.1 70.5

An analysis by GC/MS was also performed for a composite sample of thecondensed product C-10. The scan indicated presence of a large number ofcompounds. Table VIII presents the twenty most abundant compounds.

TABLE VIII The 20 most abundant compounds identified by GC/MS in sampleC-10, with relative abundance indicated in parenthesis Toluene (4.56)Trimethyl Benzene (1.52) p-Xylene (3.64) 2-Methylindene (1.44) EthylBenzene (3.27) 1,3-bis (3-phenoxyphenoxy) Benzene (1.31)1-methyl-4-(1-methylethyl) Benzene 2-ethenyl Naphtalene (1.09) (2.76)2-methyl Naphtalene (2.44) 1-methyl-4-(1-methylenethen) Benzene (0.95)Naphtalene (2.37) 2,6-dimethyl Naphtalene (0.97) Trimethyl Benzene(2.36) 1,5-dimethyl Naphtalene (0.95) o-Xylene (2.22) Fluorene (0.91)(1-methyl-2-cycloprepen-1) Benzene Indane (0.90) (1.75) 2-methylNaphtalene (1.64) 1,3-dimethyl 1H-Indene (0.87)

Analysis of the data indicates that the following families of compoundsare present: Benzene and Alkyl Benzenes, Naphtalene and AlkylNaphtalenes, Fluorenes and Indenes, Anthracenes, Phenantrenes, Pyrenes,Biphenyls, and some Phenols. Some Sulfur compounds have been identified,such as Benzothiazole, and Dibenzothiophene.

TABLE IX Estimated Average Composition for Condensed Oil Composition %w/w Hydrocarbons C6–C36  74.9% Estimated Hydrocarbons <C7   10%Estimated Sulphur compounds  4.1% Carbon  1.5% Unidentified fractions 9.5% Total 100.0%

In Test 0016 liquid samples were collected from two points: Tank 305,receiving the fraction condensed by HX03, and Tank 306, receiving thefraction condensed by HX04 (FIG. 1 b). These two condensers operatedunder the following conditions:

TABLE XI Operating conditions of condensers in Test 0016 Gas temperature(° C.) Condenser Cooling medium T₁ T₂ HX03 Water 320–380 21–24 HX04Water-glycol 21–24 7–8

A sample of condensate was analyzed before and after separation of water(L305-BP and L305D-BP, respectively), to assess it as a fuel. Twoseparate samples from Tank 305 and 306, respectively, were analyzed by asecond independent laboratory. The analysis results are presented inTable XII.

TABLE XII Analysis of condensed oil Test 0016 L-305D- L-305- L-305-L-306- Parameter Method BP⁽¹⁾ BP⁽²⁾ 1300⁽³⁾ 1300⁽⁴⁾ Sulphur (% w/w) ASTMD4294 1.814 1.759 1.34⁽⁵⁾ 1.16⁽⁵⁾ Density, 15° C. (kg/l) ASTM D12980.9421 0.9535 0.9323⁽⁶⁾ 0.8976⁽⁶⁾ Ash (% w/w) ASTM D482 0.006 0.005<0.01 <0.01 Copper corrosion, 3 hours, 100° C. ASTM D130 Cetane indexASTM D4737 Carbon residue (% w/w) ASTM D4530 5.0 3.5 Particulate matter(mg/l) ASTM D2276 100⁽⁷⁾ 30⁽⁷⁾ Flash point (° C.) ASTM D3828 AmbientAmbient <−7 <−7 Viscosity, 40° C. (cSt) ASTM D445 1.814 1.759 1.62 1.16Water by distillation % v ASTM D95 0.15 27 Strong acid number mg KOH/gASTM D664 Nil Nil Total acid number mg KOH/g ASTM D664 0.468 4.901 0.50.6 Nitrogen (ppm) ASTM D4629 3794 3642 Nitrogen (ppm) ASTM D3228 38073500 Pour point (° C.) ASTM D97 <−15 <−15 Compatibility by spot ASTMD4740 N° 4 N° 5 Stability by spot ASTM D4740 N° 4 N° 5 TSP (% w/w) IP3900.08 0.08 TSE (% w/w) IP375 0.10 0.10 Sediments by extraction (% w/w)ASTM D473 0.08 0.09 Asphaltenes (% w/w) IP143 1.1 0.6 Calorific value(MJ/kg) AS 1038.5 42.00 42.27 Metals (mg/kg) ASTM D5185 Iron <1 <1Chromium ASTM D5185 <1 <1 Cupper ASTM D5185 <1 <1 Tin ASTM D5185 <1 <1Lead IP377 <1 <1 <1⁽⁸⁾ <1⁽⁸⁾ Silica IP377 2 2 3⁽⁸⁾ 3⁽⁸⁾ Aluminum IP377 1<1 <1⁽⁸⁾ <1⁽⁸⁾ Sodium IP377(mod) 1 <1 3⁽⁸⁾ 3⁽⁸⁾ Phosphorus <1 nd nd ZincIP377 <1 <1 <1⁽⁸⁾ <1⁽⁸⁾ Calcium IP377 1 3 <1⁽⁸⁾ <1⁽⁸⁾ Lithium <1 — —Vanadium IP377 1 <1 <1⁽⁸⁾ <1⁽⁸⁾ Nickel IP377 10 2 — — ⁽¹⁾Sample taken onApr. 18, 2002 from Tank 305, analyzed by BP Refinery (Kwinana)Australia, after water setting and decanting ⁽²⁾Analysis of sampleL-305-BP before water setting and decanting ⁽³⁾Sample taken on Apr. 18,2002 from Tank 305, at 1 PM, analyzed by Geotech Australia ⁽⁴⁾Sampletaken on Apr. 18, 2002 from Tank 306, at 1 PM, analyzed by GeotechAustralia ⁽⁵⁾By method AS 1036.6.3.3 ⁽⁶⁾By method IP 190 ⁽⁷⁾Based onmethod ASTM D5452 ⁽⁸⁾By method ASTM D5185

Distillation of the lighter fraction was used to increase the flashpoint of the condensate from Test 0016, in order to conduct corrosiontests. The results are presented in Table XIV.

TABLE XIV Flash point and corrosion test before and after distillation,Test 0016 Parameter Method L-305-1300⁽¹⁾ L-306-1300DS⁽²⁾ Flash point (°C.) ASTM D3828 <−7 42 Copper corrosion, ASTM D130 — 2c 3 hours, 1000 C⁽¹⁾Sample taken on Apr. 18, 2002 from Tank 305, at 1 PM, analyzed byGeotech Australia ⁽²⁾Sample taken after distillation of 20% ofL-305-1300, analyzed by Geotech Australia

In order to study the composition of the product and characterize thedifferent fractions, the two samples from Tanks 305 and 306respectively, were analyzed using Methods USEPA 8260, 8270, and 8015B toquantify volatile and semivolatile organic compounds and establish totalhydrocarbons and their fractions. These results are presented in TableXV.

TABLE XV Analysis of condensed oil Test 0016 (mg/L) AnalyteL-305-1300⁽¹⁾ L-306-1300⁽²⁾ 1,2,4-Trimethylbenzene 5600 32001,3,5-Trimethylbenzene 2800 1500 Benzene 9300 14000  Ethylbenzene 11000 9100 Isopropylbenzene 3100 1700 Naphtalene 3700 2400 n-Propylbenzene1700  900 Styrene 6000 3800 t-butylbenzene  920  <10 Toluene 17000 18000  Xylene 24000  17000  PAH 5709 4896 Phenols 6900 3650 Hydrocarbonfractions C6–C9 290000  360000  C10–C14 270000  250000  C15–C29 290000 270000  C29–C36 74000  77000  Total 920000  960000  ⁽¹⁾Sample taken onApr. 18, 2002 from Tank 305, at 1 PM, analyzed by Geotech Australia⁽²⁾Sample taken on Apr. 18, 2002 from Tank 306, at 1 PM, analyzed byGeotech Australia

No chlorinated compounds, ethers, and chlorophenols were detected. Thecomposition of the condensed oil is presented in Table XVI:

TABLE XVI Average Composition for Condensed Oil from Test 0016Composition % w/w Hydrocarbons C6–C36   92% Estimated Sulphur compounds 5.9% Carbon  1.5% Water and sediments  0.3% Other unidentifiedcompounds  0.3% Total 100.0%

The results from all trials indicate that the majority of thehydrocarbons are aromatic in nature, predominantly alkyl Benzenes. Thecomposition of the condensate in Test 0016 is consistent with Test 0014and 0015, but has improved considerably. The condensate contains 92% ofhydrocarbons, of which over 92% are C29 or below. The high calorificvalue and low metal content are also important features of the product.Compatibility tests indicate that the product is suitable as a fuel oilblending component.

Gas is produced during the process, in the form of hydrogen, methane,and light hydrocarbons. Gas sampling and analysis was undertaken toestablish composition of the gas, determine the efficiency of thepollution control devices, and demonstrate the compliance of the plantwith stringent environmental standards. The results of the analysis ofthe gas samples are presented in the table below:

TABLE XVIII Emissions to atmosphere as detected in Test 0016 in mg/Nm³Parameter Emissions SO₂ 49⁽¹⁾ VOCs  2.0⁽²⁾ SVOCs Nd⁽³⁾ Dioxins andFurans Nd⁽⁴⁾ Particulates  4⁽⁵⁾ Nitrogen oxides 22.4⁽⁶⁾ Heavy metals 0.37⁽⁷⁾ ⁽¹⁾Sampling method: USEPA Method 1 and Method 2, Analysismethod: USEPA Method 6C ⁽²⁾Sampling method: USEPA Method 1 and Method 2,Analysis method: USEPA Method 18 and Method 0030 ⁽³⁾Sampling method:USEPA Method 1 and Method 2, Analysis method: USEPA Modified Method 5⁽⁴⁾Sampling method: USEPA Method 1 and Method 2, Analysis method: USEPAMethod 23 ⁽⁵⁾Sampling method: USEPA Method 1 and Method 2, Analysismethod: USEPA Method 5 ⁽⁶⁾Sampling method: USEPA Method 1 and Method 2,Analysis method: USEPA Method 7E ⁽⁷⁾Sampling method: USEPA Method 1 andMethod 2, Analysis method: USEPA Method 29

TABLE XIX Composition of hydrocarbons C1 to C6 before and after theafterburner in mg/Nm³ Analyte Before afterburner After afterburnerMethane 4071 Nd Ethene 2125 Nd Ethane 3348 Nd Propane 2946  29 Butane2356 116 Pentane 1031 562 Hexane 226 200

The gas has high concentrations of hydrocarbons with high calorificvalues.

The third stream produced from the pyrolysis process is char. Potentialuses of the char obtained from the pyrolysis of tyres include its reuseas carbon black, its use as a solid fuel, and applications asadsorbents. The char was analyzed to determine Sulphur and hydrocarbonfractions. The results are presented in Table XXI.

TABLE XXI Analysis of hydrocarbons and Sulphur in char samples ParameterS-1 S-2 S-3 S-6 Sulphur (% w/w) 0.82 0.81 1.20 1.50 Ash (% w/w) 89.586.2 71.7 Not analized Moisture (% w/w) 0.0 0.1 0.3 0.1 Hydrocarbonfractions (mg/kg) C6–C9 <25 <25 160 25 C10–C14 200 610 1100 51 C15–C293500 5000 6600 1200 C29–C36 4700 4600 4700 1300 Total 8500 8500 100002600

The changes in the design of TDPP-III compared to TDPP-II produced achar with only traces of Toluene and Xylene, whilst no other organiccompounds were detected. The reduced level of hydrocarbons produced areduction in the calorific value and a decrease in the ratio of mass ofchar produced per mass of tire. This supports a model where gas andcondensate are maximized in detriment of the mass of char produced,resulting in an improved model for energy production based on use of gasand liquid only. The distribution of compounds between char and oil isshown in Table XXIII.

TABLE XXIII Analysis of char and oil from Test 0016 Analyte S-OF-1300⁽¹⁾L-305-1300⁽²⁾ Sulphur (% w/w) 0.57 1.34 Ash (% w/w) 53 <0.01 Calorificvalue (MJ/kg) 10.61 42.00 Iodine number (mg I₂ absorbed/g 75 — carbon)Hydrocarbon fractions (mg/kg) C6–C9 Nd 290000 C10–C14 Nd 270000 C15–C29Nd 290000 C29–C36 Nd 74000 Total Nd 920000 1,2,4-Trimethylebenzene <1.05600 1,3,5-Trimethylebenzene <1.0 2800 Benzene <1.0 9300 Ethylbenzene<1.0 11000 Isopropylbenzene <1.0 3100 Naphtalene <1.0 3700n-Propylbenzene <1.0 1700 Styrene <1.0 6000 t-butylbenzene <1.0 920Toluene 12 17000 Xylene 2.3 24000 PAH Nd 5709 Phenols Nd 6900 ⁽¹⁾Sampletaken on Apr. 18, 2002 from out feed bin, at 1 PM, analyzed by GeotechAustralia ⁽²⁾Sample taken on Apr. 18, 2002 from Tank 305, at 1 PM,analyzed by Geotech Australia

The mass balance has been estimated based on field measurements takenduring Test 0014, 0015, and 0016. The gas produced from the pyrolysis ofthe tyres was destroyed by combustion in the After Burner. A balance ofmass and an estimate of the elemental composition of the initial productand the produced char and oil is presented in Table XXVIII.

TABLE XXVIII Estimated balance of mass from elemental composition oftyres, char, and condensed oil Per kg of tyres Source Carbon HydrogenOxygen Nitrogen Sulfur Other Total Tyres % w/w 1 (1) 78.38% 6.48% 3.86%0.18% 1.84% 9.26% 100.00% kg/kg tyres 0.784 0.065 0.039 0.002 0.0180.093 1.000 Char % w/w 0.322 (2) 35.54% 0.00% 14.78% 0.00% 0.57% 49.11%100.00% kg/kg tyres 0.114 — 0.048 — 0.002 0.158 0.322 Oil % w/w 0.394(3) 90.92% 7.58% 0.00% 0.00% 1.34% 1.50% 101.34% kg/kg tyres 0.358 0.0300.000 0.000 0.005 0.006 0.399 Gas % w/w 0.36 (4) 87.06% 9.78% 0.00%0.00% 3.16% 0.00% 100.00% kg/kg tyres 0.31 0.03 — — 0.01 — 0.36Estimated molar ratios Carbon to hydrogen Tyres 1.0 Oil 1.0 Gas 0.7 (1)Elemental analysis performed by Geotech Australia (2) Elemental analysisperformed by Geotech Australia, sulfur analysis by Geotech Australia,and “other” includes adjusted ash content (3) Estimated from fractionsfor total petroleum hydrocarbons, as analysed by Geotech Australia. Aweighted average molecular weight has been calculated from eachhydrocarbon fraction, allowing for double bonds (4) Estimated frombalance of mass for carbon, hydrogen, and sulfur

Table XXVIII has been used to estimate the composition of the gas. Themodel simplifies the composition to Methane, Ethylene, Carbon Monoxideand Dioxide, and Hydrogen Sulfide, as these five gases account to over96% of the gases, although other gases are present. The data ispresented in Table XXVIIIb.

TABLE XXVIIIb Estimated composition of pyrolysis gas Test 0016 Per kg ofParameter Total tyres Mass into gas phase 0.360 kg Methane 42.86% 0.154kg Ethylene 23.81% 0.086 kg CO 8.33% 0.030 kg CO₂ 16.66% 0.060 kg H₂S1.98% 0.007 kg Total 93.64% 0.337 kg

The results of gas analysis confirm that Methane Is the most abundantgas, with ethane and ethylene also present in significant quantities.The percentages of the gas mix are presented in Table XXVIIIc, based onresults presented in Table XIX.

TABLE XXVIIIc Composition of hydrocarbons C1 to C6 before theafterburner in mg/Nm³ Analyte Concentration (mg/Nm³) % Methane 407144.89% Ethylene 2125 13.39% Ethane 3348 19.69% Propane 2946 11.81%Butane 2356 7.17% Pentane 1031 2.60% Hexane 226 0.46%

In order to provide an estimate of calorific value from the gas, anaverage calorific value was calculated using 50 MJ/kg as a conservativevalue. The estimates are presented in Table XXIX.

TABLE XXIX Energy and generation estimate for pyrolysis gas ParameterTest 0014 Gas produced 0.360 kg/kg of tyres Calorific value 50 MJ/kg ofgas Total energy from Methane gas 8.08 MJ/kg of tyres only2. Plastics

Process conditions for the pyrolysis of plastics are presented in TableXXX.

TABLE XXX Process conditions Parameter Temperature retort 450–700° C.Feed rate 200–2000 kg/hour Temperature condenser outlet 15° C. maxTemperature afterburner 860° C. min Condensed pyrolysis oil 50–70% w/wPyrolysis char 5–10% w/w Gas 20–45% w/w (estimated)

The process' temperature can be regulated to increase the production ofpyrolysis gas. The gas stream can be used directly as fuel for a gasturbine, with solids removed in the HTF. The composition of the gas andoil varies with the fed plastic mix. Likely compositions are as follows:

TABLE XXXI Process outputs Plastic fed Outputs Polypropylene Pyrolysisoil is composed of hydrocarbons with 6 to 15 carbons, 5–10% water, lessthan 100 ppm Sulfur, less than 30 ppm Chlorine, less than 20 ppmcombined metals. Oil meets CIMAC fuel specifications. PolystyrenePyrolysis oil is composed of hydrocarbons with 8 to 16 carbons, 5–10%water, less than 100 ppm Sulfur, less than 30 ppm Chlorine, less than 20ppm combined metals. The oil has 50–70% aromatic compounds, mainly ethylbenzene, toluene, xylene, and methyl- ethylebenzene. Oil meets CIMACfuel specifications.

Solids extracted from the retort contain carbon, silicates, metaloxides, sulfates, alumina, and other compounds.

3. Grease

Tests were conducted to demonstrate the applicability of the apparatusto the processing of waste hydrocarbon grease, using a configurationthat included a water-cooled condenser and the After Burner. Feeding ofthe grease was achieved using a positive displacement pump.

Process conditions are summarized in Table XXXII.

TABLE XXXII Process conditions Parameter Temperature retort 400° C. Feedrate 200 kg/hour Time 28 hours Pressure HTF clean side 0.1 in H₂OTemperature condenser outlet 15° C. max Temperature afterburner 860° C.min Condensed pyrolysis oil 40% w/w Pyrolysis char 21% w/w Gas 39% w/w(estimated)

The trial was run at temperatures of 400–430° C.

Analysis of the condensed oil was performed, with the objective ofevaluating the pyrolysis oil as a fuel. The results are summarized inTable XXXIII.

TABLE XXXIII Analysis of condensed oil Parameter Method PH010102A Sulfur(% w/w) ICP AES 0.17 Density, 15° C. (kg/l) ASTM D4052 0.8649 Ash (%w/w) ASTM D482 0.0024 Copper corrosion, 3 hours, 100° C. ASTM D130 1bCetane index ASTM D976 55 Carbon residue (% w/w) ASTM D524 1.68 Water &sediments (% v/v) ASTM D2709 0.01 Flash point (° C.) ASTM D3828 <30Viscosity, 40° C. (cSt) ASTM D445 7.34 Distillation, simulated D86 ASTMD2887 10% recovered ° C. 165.5 20% recovered ° C. 235.0 30% recovered °C. 295.5 50% recovered ° C. 389.0 70% recovered ° C. 448.5 80% recovered° C. 479.0 90% recovered ° C. 510.5

The sample was subjected to flash distillation producing a final productwith a flash point of 71° C. that met specifications as a fuel forcombustion engines, similar in properties to marine diesel fuel, basedon CIMAC standards.

Modifications and variation such as would be apparent to the skilledaddressee are considered to fall within the scope of the presentinvention.

1. An apparatus, when used for the processing of a carbon-containingpolymeric material, the apparatus comprising a retort assembly whichincludes a retort disposed at least partially within a combustionchamber, the retort containing an inert heat-transfer medium, and anagitation means and the combustion chamber having heating means toindirectly heat the retort, wherein the agitation means is adapted toagitate the inert heat transfer medium and the carbon containingpolymeric material.
 2. An apparatus as claimed in claim 1 characterisedin that the agitation means is adapted to agitate the inert heattransfer medium and the carbon containing polymeric material to create afluidised bed, or fluidised bed-like effect.
 3. An apparatus as claimedin claim 1 characterised in that the agitation means is controllable,whereby the residence time of the solid material in the retort may becontrolled.
 4. An apparatus as claimed claim 1 characterised in that alongitudinal axis of the retort is inclined to the horizontal, and theretort is bottom fed.
 5. An apparatus as claimed in claim 1characterised in that the agitation means is further adapted tofacilitate the transport of the polymeric material and the inertheat-transfer medium through the retort.
 6. An apparatus as claimed inclaim 5 characterised in that the agitation means is provided in theform of an auger.
 7. An apparatus as claimed in claim 1 characterised inthat the retort is adapted to allow the exclusion of air or oxygen. 8.An apparatus as claimed in claim 1 characterised in that the retortcomprises a substantially cylindrical body.
 9. An apparatus as claimedin claim 8 characterised in that the substantially cylindrical body ismounted for rotation about its longitudinal axis.
 10. An apparatus asclaimed in claim 1 characterised in that the retort is substantiallysurrounded by the combustion chamber to enable direct heating of theretort.
 11. An apparatus as claimed in claim 1 characterised in that theapparatus further comprises a high temperature filter through which thegaseous stream may pass after leaving the retort and prior to enteringan afterburner.
 12. An apparatus as claimed in claim 1 characterised inthat the heat transfer medium is provided in the form of sodiumsilicate, or sand.
 13. An apparatus as claimed in claim 1 characterisedin that the heat transfer medium is provided in the form of alumina. 14.An apparatus as claimed in claim 1 characterised in that the retortcontains one or more catalysts.
 15. An apparatus as claimed in claim 1characterised in that the apparatus additionally comprises anafterburner, means to transfer a gaseous stream from the retort to theafterburner for combustion and means for passing the combustion gasesfrom the afterburner to the retort assembly to provide heat for heatingcarbon-containing polymeric material in the retort.
 16. An apparatus asclaimed in claim 1 characterised in that the apparatus further comprisesone or more condensers wherein each condenser is adapted to condensegaseous products produced by heating the polymeric material.
 17. Anapparatus as claimed in claim 1 characterised in that the apparatusfurther comprises a combustion engine, wherein the engine is adapted toreceive and be fuelled by condensed gaseous products produced by heatingthe polymeric material until it decomposes, pyrolyses or desorbs.
 18. Anapparatus as claimed in claim 17 characterised in that the engine is agas turbine adapted to generate electricity from the gases produced fromthe decomposition of the polymeric materials, without priorcondensation.
 19. A method for the processing of carbon-containingpolymeric material, the method comprising the steps of: introducing thecarbon-containing polymeric material into the retort of a retortassembly which includes a retort disposed at least partially within thecombustion chamber, the retort containing an inert heat-transfer mediumand an agitation means, wherein the agitation means is adapted toagitate the inert heat transfer medium and the carbon containingpolymeric material, the combustion chamber having heating means toindirectly heat the rotatable retort; heating the carbon-containingpolymeric material and the inert heat transfer medium to cause such toat least partially decompose; discharging processed carbon-containingpolymeric material from the retort.
 20. A method according to claim 19characterised in that the agitation means is adapted to agitate theinert heat transfer medium and the carbon containing polymeric materialto create a fluidised bed, or fluidised bed-like effect, and the methodincludes the step of agitating the inert heat transfer medium and thecarbon containing polymeric material to produce a fluidised bed orfluidised bed effect.
 21. A method according to claim 19 characterisedin that the agitation means is controllable, whereby the residence timeof the solid material in the retort may be controlled.
 22. A methodaccording to claim 19 characterised in that the steps of the method areperformed concurrently.
 23. A method according to claim 19 characterisedin that the method comprises the further step of: controlling the rateof passage of the carbon-containing polymeric material through theretort, such that the carbon-containing polymeric material is retainedin the retort for a predetermined residence time.
 24. A method accordingto claim 19 characterised in that the step of heating thecarbon-containing polymeric material to cause such to at least partiallydecompose is performed in a substantially oxygen-free atmosphere.
 25. Amethod according to claim 24 characterised in that the step of heatingthe carbon-containing polymeric material to cause such to at leastpartially decompose is performed in an inert gas atmosphere.
 26. Amethod according to claim 24 characterised in that the step of heatingthe carbon-containing polymeric material to cause such to at leastpartially decompose is performed in an atmosphere substantiallycomprising nitrogen gas.
 27. A method according to claim 19characterised in that the carbon-containing polymeric material isprovided in the form of one or more tyres.
 28. A method according toclaim 27 characterised in that the step of heating the carbon-containingpolymeric material to cause such to at least partially decompose morespecifically comprises the step of heating the tyres to between about400–800° C.
 29. A method according to claim 27 characterised in that thestep of heating the carbon-containing polymeric material to cause suchto at least partially decompose more specifically comprises the step ofheating the tyres to between about 450–600° C.
 30. A method according toclaim 27 characterised in that the step of heating the carbon-containingpolymeric material to cause such to at least partially decompose morespecifically comprises the step of heating the tyres to about 450° C.31. A method according to claim 27 characterised in that the residencetime of the tyres in the retort is between about 30 and 240 minutes. 32.A method according to claim 27 characterised in that the residence timeof the tyres in the retort is between about 45 and 180 minutes.
 33. Amethod according to claim 27 characterised in that the residence time ofthe tyres in the retort is approximately 130 minutes.
 34. A methodaccording to claim 27 characterised in that, before the step ofintroducing the tyres into the retort, the method of the presentinvention comprises the preliminary step of shredding the tyres.
 35. Amethod according to claim 19 characterised in that the carbon-containingpolymeric material is provided in the form of one or more plastics. 36.A method according to claim 19 wherein the carbon-containing polymericmaterial is provided in the form of one or more plastics characterisedin that the step of heating the plastics material to cause such to atleast partially decompose more specifically comprises the steps ofheating the carbon-containing polymeric material to melt such beforeheating the carbon-containing polymeric material to pyrolyse such.
 37. Amethod according to claim 35 characterised in that the plastics includeone or more halogen containing polymers, and the method comprises thestep of treating a gas stream produced from the pyrolysis to removehydrogen chloride.
 38. A method according to claim 35 characterised inthat the plastics are heated to between about 300 and 1200° C.
 39. Amethod according to claim 35 characterised in that the plastics areheated to between about 450–1000° C.
 40. A method according to claim 35characterised in that the plastics are heated to about 550° C.
 41. Amethod according to claim 35 characterised in that the residence time ofthe plastics in the retort is between about 30 and 240 minutes.
 42. Amethod according to claim 35 characterised in that the residence time isbetween about 45 and 120 minutes.
 43. A method according to claim 35characterised in that the residence time is approximately 80 minutes.44. A method according to claim 19 characterised in that the carboncontaining polymeric material is provided in the form of a cellulosicmaterial, the cellulosic fibres thereof being pyrolysed to producefractions of shorter molecules with properties consistent with those ofliquid fuels obtained from biomass.
 45. A method according to claim 44characterised in that the step of heating the cellulosic material tocause such to at least partially decompose more specifically comprisesthe step of heating the cellulosic material to between about 400 and800° C.
 46. A method according to claim 44 characterised in that thestep of heating the cellulosic material to cause such to at leastpartially decompose more specifically comprises the step of heating thecellulosic material to between about 450 and 800° C.
 47. A methodaccording to claim 44 characterised in that the step of heating thecellulosic material to cause such to at least partially decompose morespecifically comprises the step of heating the cellulosic material toabout 500° C.
 48. A method according claim 44 characterised in that theresidence time of the cellulosic material in the retort is between about30 and 240 minutes.
 49. A method according to claim 44 characterised inthat the residence time of the cellulosic material in the retort isbetween about 45 and 120 minutes.
 50. A method according to claim 44characterised in that the residence time of the cellulosic material inthe retort is approximately 80 minutes.
 51. A method according to claim19 characterised in that the method further comprises the step of:reducing the pressure in the retort to enable lower temperatures to beused.
 52. A method according to claim 19 characterised in that the stepof discharging processed carbon-containing polymeric material from theretort includes separating the heat transfer medium from the processedcarbon-containing polymeric material.
 53. A method according to claim 52characterised in that the step of separating the heat transfer mediumfrom the processed carbon-containing polymeric material morespecifically comprises: separating the heat transfer medium from theprocessed carbon-containing polymeric material based on densitydifferences.
 54. A method according to claim 19 characterised in that,where the carbon-containing polymeric material decomposes into a gaseousstream, the method comprises the step of: filtering the gaseous streamto remove particulate material therefrom.
 55. A method according toclaim 19 characterised in that, where the carbon-containing polymericmaterial decomposes into a gaseous stream, the method comprises the stepof: condensing at least a portion of the gaseous stream to produce acondensate.
 56. A method according to claim 55 characterised in that thestep of condensing at least a portion of the gaseous stream morespecifically comprises: fractionating at least a portion the gaseousstream to produce a range of condensate fractions.
 57. A methodaccording to claim 55 characterised in that the method comprises thefurther steps of: fractionating at least a portion the gaseous stream toproduce a range of condensate fractions; and subjecting the condensateto flash distillation.
 58. A method according to claim 54 characterisedin that the method comprises the further step of: combusting the gaseousstream to provide heat for heating the carbon-containing polymericmaterial.
 59. A method according to any one of claims 54 characterisedin that the method comprises the further step of: combusting the gaseousstream in a gas turbine to generate heat and electricity.
 60. A methodaccording to claim 54 characterised in that the method comprises thefurther step of: combusting the gaseous stream in an afterburner orthermal oxidiser.
 61. A method according to claim 19 characterised inthat, where the carbon-containing polymeric material is provided in theform of a solid, the carbon-containing polymeric material may be passedthrough a grizzly or sieve, to remove oversized material, prior to beingintroduced into the retort.
 62. A method according to claim 19characterised in that, where the carbon-containing polymeric material isprovided in the form of a solid, the carbon-containing polymericmaterial may be shredded or milled to reduce particle size and mayinclude a separation stage, during which metals or other material may beseparated from the carbon-containing polymers.
 63. A method accordingclaim 19 characterised in that, where the carbon-containing polymericmaterial is provided in the form of a liquid, the water content of thecarbon-containing polymeric material is minimised prior to introducingsuch into the retort, optionally by preheating the liquidcarbon-containing polymeric material to boil off any water.